/*!
 * jQuery resize event - v1.1 - 3/14/2010
 * http://benalman.com/projects/jquery-resize-plugin/
 *
 * Copyright (c) 2010 "Cowboy" Ben Alman
 * Dual licensed under the MIT and GPL licenses.
 * http://benalman.com/about/license/
 */

// Script: jQuery resize event
//
// *Version: 1.1, Last updated: 3/14/2010*
//
// Project Home - http://benalman.com/projects/jquery-resize-plugin/
// GitHub       - http://github.com/cowboy/jquery-resize/
// Source       - http://github.com/cowboy/jquery-resize/raw/master/jquery.ba-resize.js
// (Minified)   - http://github.com/cowboy/jquery-resize/raw/master/jquery.ba-resize.min.js (1.0kb)
//
// About: License
//
// Copyright (c) 2010 "Cowboy" Ben Alman,
// Dual licensed under the MIT and GPL licenses.
// http://benalman.com/about/license/
//
// About: Examples
//
// This working example, complete with fully commented code, illustrates a few
// ways in which this plugin can be used.
//
// resize event - http://benalman.com/code/projects/jquery-resize/examples/resize/
//
// About: Support and Testing
//
// Information about what version or versions of jQuery this plugin has been
// tested with, what browsers it has been tested in, and where the unit tests
// reside (so you can test it yourself).
//
// jQuery Versions - 1.3.2, 1.4.1, 1.4.2
// Browsers Tested - Internet Explorer 6-8, Firefox 2-3.6, Safari 3-4, Chrome, Opera 9.6-10.1.
// Unit Tests      - http://benalman.com/code/projects/jquery-resize/unit/
//
// About: Release History
//
// 1.1 - (3/14/2010) Fixed a minor bug that was causing the event to trigger
//       immediately after bind in some circumstances. Also changed $.fn.data
//       to $.data to improve performance.
// 1.0 - (2/10/2010) Initial release

(function($, window, undefined) {
    '$:nomunge'; // Used by YUI compressor.

    // A jQuery object containing all non-window elements to which the resize
    // event is bound.
    var elems = $([]),

        // Extend $.resize if it already exists, otherwise create it.
        jq_resize = $.resize = $.extend($.resize, {}),

        timeout_id,

        // Reused strings.
        str_setTimeout = 'setTimeout',
        str_resize = 'resize',
        str_data = str_resize + '-special-event',
        str_delay = 'delay',
        str_throttle = 'throttleWindow';

    // Property: jQuery.resize.delay
    //
    // The numeric interval (in milliseconds) at which the resize event polling
    // loop executes. Defaults to 250.

    jq_resize[str_delay] = 250;

    // Property: jQuery.resize.throttleWindow
    //
    // Throttle the native window object resize event to fire no more than once
    // every <jQuery.resize.delay> milliseconds. Defaults to true.
    //
    // Because the window object has its own resize event, it doesn't need to be
    // provided by this plugin, and its execution can be left entirely up to the
    // browser. However, since certain browsers fire the resize event continuously
    // while others do not, enabling this will throttle the window resize event,
    // making event behavior consistent across all elements in all browsers.
    //
    // While setting this property to false will disable window object resize
    // event throttling, please note that this property must be changed before any
    // window object resize event callbacks are bound.

    jq_resize[str_throttle] = true;

    // Event: resize event
    //
    // Fired when an element's width or height changes. Because browsers only
    // provide this event for the window element, for other elements a polling
    // loop is initialized, running every <jQuery.resize.delay> milliseconds
    // to see if elements' dimensions have changed. You may bind with either
    // .resize( fn ) or .bind( "resize", fn ), and unbind with .unbind( "resize" ).
    //
    // Usage:
    //
    // > jQuery('selector').bind( 'resize', function(e) {
    // >   // element's width or height has changed!
    // >   ...
    // > });
    //
    // Additional Notes:
    //
    // * The polling loop is not created until at least one callback is actually
    //   bound to the 'resize' event, and this single polling loop is shared
    //   across all elements.
    //
    // Double firing issue in jQuery 1.3.2:
    //
    // While this plugin works in jQuery 1.3.2, if an element's event callbacks
    // are manually triggered via .trigger( 'resize' ) or .resize() those
    // callbacks may double-fire, due to limitations in the jQuery 1.3.2 special
    // events system. This is not an issue when using jQuery 1.4+.
    //
    // > // While this works in jQuery 1.4+
    // > $(elem).css({ width: new_w, height: new_h }).resize();
    // >
    // > // In jQuery 1.3.2, you need to do this:
    // > var elem = $(elem);
    // > elem.css({ width: new_w, height: new_h });
    // > elem.data( 'resize-special-event', { width: elem.width(), height: elem.height() } );
    // > elem.resize();

    $.event.special[str_resize] = {

        // Called only when the first 'resize' event callback is bound per element.
        setup: function() {
            // Since window has its own native 'resize' event, return false so that
            // jQuery will bind the event using DOM methods. Since only 'window'
            // objects have a .setTimeout method, this should be a sufficient test.
            // Unless, of course, we're throttling the 'resize' event for window.
            if(!jq_resize[str_throttle] && this[str_setTimeout]) {
                return false;
            }

            var elem = $(this);

            // Add this element to the list of internal elements to monitor.
            elems = elems.add(elem);

            // Initialize data store on the element.
            $.data(this, str_data, {
                w: elem.width(),
                h: elem.height()
            });

            // If this is the first element added, start the polling loop.
            if(elems.length === 1) {
                loopy();
            }
        },

        // Called only when the last 'resize' event callback is unbound per element.
        teardown: function() {
            // Since window has its own native 'resize' event, return false so that
            // jQuery will unbind the event using DOM methods. Since only 'window'
            // objects have a .setTimeout method, this should be a sufficient test.
            // Unless, of course, we're throttling the 'resize' event for window.
            if(!jq_resize[str_throttle] && this[str_setTimeout]) {
                return false;
            }

            var elem = $(this);

            // Remove this element from the list of internal elements to monitor.
            elems = elems.not(elem);

            // Remove any data stored on the element.
            elem.removeData(str_data);

            // If this is the last element removed, stop the polling loop.
            if(!elems.length) {
                clearTimeout(timeout_id);
            }
        },

        // Called every time a 'resize' event callback is bound per element (new in
        // jQuery 1.4).
        add: function(handleObj) {
            // Since window has its own native 'resize' event, return false so that
            // jQuery doesn't modify the event object. Unless, of course, we're
            // throttling the 'resize' event for window.
            if(!jq_resize[str_throttle] && this[str_setTimeout]) {
                return false;
            }

            var old_handler;

            // The new_handler function is executed every time the event is triggered.
            // This is used to update the internal element data store with the width
            // and height when the event is triggered manually, to avoid double-firing
            // of the event callback. See the "Double firing issue in jQuery 1.3.2"
            // comments above for more information.

            function new_handler(e, w, h) {
                var elem = $(this),
                    data = $.data(this, str_data) || {};

                // If called from the polling loop, w and h will be passed in as
                // arguments. If called manually, via .trigger( 'resize' ) or .resize(),
                // those values will need to be computed.
                data.w = w !== undefined ? w : elem.width();
                data.h = h !== undefined ? h : elem.height();

                old_handler.apply(this, arguments);
            };

            // This may seem a little complicated, but it normalizes the special event
            // .add method between jQuery 1.4/1.4.1 and 1.4.2+
            if($.isFunction(handleObj)) {
                // 1.4, 1.4.1
                old_handler = handleObj;
                return new_handler;
            } else {
                // 1.4.2+
                old_handler = handleObj.handler;
                handleObj.handler = new_handler;
            }
        }

    };

    function loopy() {

        // Start the polling loop, asynchronously.
        timeout_id = window[str_setTimeout](function() {

            // Iterate over all elements to which the 'resize' event is bound.
            elems.each(function() {
                var elem = $(this),
                    width = elem.width(),
                    height = elem.height(),
                    data = $.data(this, str_data);

                // If element size has changed since the last time, update the element
                // data store and trigger the 'resize' event.
                if(width !== data.w || height !== data.h) {
                    elem.trigger(str_resize, [data.w = width, data.h = height]);
                }

            });

            // Loop.
            loopy();

        }, jq_resize[str_delay]);

    };

})(jQuery, this);

